International Business Machines (IBM) (Boca Raton, Fla.)

To many people, the terms “IBM” and “computer” are synonymous. Before micros appeared, IBM owned the mainframe market, but was feeling competitive pressure from companies like Digital Equipment and Data General. Their minicomputers were stealing sales away from IBM. By the late 1970s, it was clear that IBM would have to expand its product line into small systems.

IBM sold systems that could be considered microcomputers as early as 1975 with the 5100. Definitely not a hobbyist machine at the price, the 5100 was aimed at industrial, commercial, and professional markets. Although sold as a transportable, it was anything but at 50 pounds. IBM did not sell the Problem Solver Library, but rented it at $500. Later versions used floppy drives in place of the tape storage unit. The IBM 5100 is a rare and desirable collectible today. The 5120 and Datamaster systems followed the 5100.

The company didn’t put its full weight behind a microcomputer product until it launched the IBM PC in August 1981. Some computer industry watchers of the time thought that the new IBM PC was doomed to failure. After all, it didn’t run the leading microcomputer business operating system of the day, CP/M. IBM later offered CP/M as an option, but it hardly mattered. The IBM PC changed the microcomputer world by establishing a standard that almost every manufacturer eventually would adopt. IBM briefly offered a PC1 version of the Model 5150 that came standard with only 16K of RAM, expandable to 64K. PC1 examples are rare and command a 20 to 50 percent premium over PC2 values, depending on condition and completeness.

More expansion bus slots and greater mass storage capabilities were the most significant improvements that the PC XT (for Extended Technology) made over the PC. IBM offered a version of the PC XT that would run its mainframe applications. The Personal Computer XT/370 used the Virtual Machine/Personal Computer (VM/PC) control program that provided compatibility with the Virtual Machine/Conversational Monitor System (VM/CMS) mainframe program. IBM developed the Portable PC in response to the popularity of other vendors’ PC-compatible transportables. Its innards were based on the PC XT.

The PC AT was at the time the most significant upgrade from the original PC. Third-party tests showed that it was 2.5 times faster than the PC, and the PC AT could be expanded to 3MB of memory by using one of its expansion slots. IBM later added a PC AT Model 339, which came with 512K of RAM, a 30MB hard disk drive, and the IBM Enhanced Personal Computer Keyboard. Eventually, an 8MHz 80286 replaced the slower 6MHz version. The PC AT sold in great numbers, but finding one today that isn’t scarred from years of use is uncommon.

When word got out that IBM was about the enter the home PC market with a computer code-named Peanut, sales of many existing home systems dropped as consumers anticipated the launch. The PCjr formally launched with great fanfare. However, the PCjr was not the success IBM had hoped for. The original keyboard was a mushy Chiclet style (later replaced with a more conventional keyboard). The PCjr was not compatible with many applications written for the PC, and PCjr cartridge-based software was slow to be released. IBM designed an infrared keyboard interface (a keyboard cable was optional) so that families could use the TV as the monitor and type from anywhere in the living room, but the technology proved problematic. In a school setting, for example, kids soon learned that they could point the keyboard at and control systems other than their own. The PCjr was sold in Japan as the IBM Personal Computer JX.

IBM also missed the mark with its first laptop, the PC Convertible. It was bigger, heavier, and more expensive than some of its competitors’ models. Items found standard on other systems, such as serial and parallel interfaces, were options on the Convertible. Consequently, the Convertible did not sell well. It was IBM’s first laptop computer, and as such is collectible. The Convertible’s LCD is detachable so that users could set a CRT display atop the computer; some surviving examples might be separated from their LCDs as a result.

In 1987, IBM introduced a new line of systems, the Personal System/2 (PS/2). Models ranges from the entry-level 25 to the 80 tower system for power users. The higher end models used IBM’s new Micro Channel system bus for higher performance and optionally the new OS/2 operating system.

IBM sold a Personal Typing System based on the PS/2 Model 30 and IBM printer through its typewriter dealers. The Model 80 could be used as a high-end personal computer or as a network server. Its tower cabinet–the same used for the Model 60–allowed for a great deal of expandability.